# Getting ready for a meeting
Before a meeting, make sure your device works with Amazon Chime. You can choose your preferred video and audio sources before entering a meeting. If using an external device for audio or video, such as a headset or web cam, ensure the devices are compatible with Amazon Chime. You can also set up phone numbers for dialing in to a meeting from a phone, as well as have Amazon Chime call you when a meeting starts.
**Topics**
+ [Using the Amazon Chime Readiness Checker](checker.md)
+ [Setting video and audio sources](set-video-audio.md)
+ [Using the Call me feature](enable-call-me.md)
# Using the Amazon Chime Readiness Checker
To verify that your device is compatible with Amazon Chime, use the Amazon Chime Readiness Checker at [https://app.chime.aws/check](https://app.chime.aws/check). The Amazon Chime Readiness Checker runs in your browser and verifies that your device is compatible with the Amazon Chime desktop client, web app, and mobile app.
The Amazon Chime Readiness Checker checks the speaker, microphone, camera, screen sharing, and connectivity for the following conditions.
**Speaker**
Is the speaker device connected and turned on?
Is the volume turned up?
Confirm your default system speaker device.
Check your browser settings and confirm that Amazon Chime has permission to access your speaker device.
**Microphone**
Is the microphone device connected and turned on?
Confirm your default system microphone device.
Check your browser settings to confirm that Amazon Chime has permission to access your microphone device.
**Camera**
Is the camera connected and turned on?
Confirm your default system camera.
Check your browser settings to confirm that Amazon Chime has permission to access your camera.
**Screen share**
Are you using the Google Chrome or Mozilla Firefox browser?
Update your browser to the latest version. Screen share is available for Chrome version 72 and Firefox version 66 or later, as well as the Amazon Chime desktop client.
**Connectivity**
For information about connectivity requirements, contact your Amazon Chime administrator.
# Setting video and audio sources
In the desktop client and web app, you can set your video and audio sources before you join an Amazon Chime meeting. If you know that your current video and audio sources work, you can [join the meeting](join-meetings.md).
When you accept a call from a meeting, or you choose a link to a meeting, the **Device preview** dialog box appears. You can use the dialog box to change your audio and video sources before you join.
This image shows the **Device preview** dialog box.
![\[Image showing the Device preview dialog and its options.\]](http://docs.aws.amazon.com/chime/latest/ug/images/device-preview-annotated.png)
**Note**
If the Device preview dialog box doesn't appear, you can change your audio and video sources while in the meeting. For more information, see [Using audio during meetings](using-audio.md) and [Using video during meetings](use-video.md).
If you see the Device preview dialog box, but you don't see your video or audio sources, choose the Settings icon.
![\[A typical settings icon with a gear.\]](http://docs.aws.amazon.com/chime/latest/ug/images/join-dialog-settings.png)
If you chose to hide the Device preview dialog box, and you want to show again, change the global setting. For more information, see [Amazon Chime global program settings](chm-settings.md).
The following topics explain how to use the options shown in the image above.
**Topics**
+ [Setting video sources](#set-video)
+ [Setting audio sources](#set-audio)
+ [Setting phone numbers](#set-phone-numbers)
## Setting video sources
If you have more than one video device available, such as an external and built-in camera, you can choose between them. You can also enable or disable background blurring and set the blur strength.
**To set video sources**
1. Answer the call from a meeting, or select the link the link in the meeting invitation.
The **Device preview** dialog box appears.
1. Under **Video settings**, from the dropdown list of available cameras, select the one that you want to use.
1. (Optional) Select or clear the **Blur background** check box.
1. (Optional) If you turn on **Blur background**, open the dropdown list and choose the blur strength.
## Setting audio sources
If you have more than one set of speakers or microphones available, you can choose between them. You can also enable or disable Voice Focus noise reduction, choose to join a meeting with your audio muted, and enable or disable automatic sound leveling.
**To change audio settings**
1. Answer the call from a meeting, or select the link the link in the meeting invitation.
The **Device preview** dialog box appears.
1. Under **Audio settings**, choose the **Computer** tab.
1. Under **Select your speakers**, choose a device from the dropdown menu.
1. Under **Microphone**, choose a device from the dropdown menu
1. (Optional) To turn on Amazon Voice Focus, select the **Amazon Voice Focus** checkbox. To turn this feature off, clear the checkbox.
1. (Optional) To mute your microphone when you first join the call, select the **Join muted** checkbox. To join the call with your microphone turned on, clear the checkbox.
**Note**
Meeting organizers can mute all attendees until after they join. When this feature is turned on, the **Join muted** checkbox is turned on and becomes unavailable to change.
1. (Optional) To turn on automatic adjustment of audio levels during a call, select the Auto-adjust audio levels checkbox. To turn this feature off, clear the checkbox.
**Note**
If you turn off automatic adjustment of audio levels, you will need to adjust your microphone and speaker volume manually.
## Setting phone numbers
In addition to setting video and audio sources, you can configure phone numbers for dialing in to a meeting from a phone.
**Note**
If you don't need to configure additional dial-in phone numbers, you can skip this section and [join the meeting](join-meetings.md).
**To change your dial-in settings**
1. Answer the call from a meeting, or select the link the link in the meeting invitation.
The **Device preview** dialog box appears.
1. Under **Audio settings**, choose the **Phone** tab.
1. Under **Dial-in**, select a phone number from the dropdown list. Amazon Chime provides a range of default phone numbers, but you may see additional numbers specific to your organization.
1. Choose **Dial**.
# Using the Call me feature
The **Call me** feature enables Amazon Chime to call your phone and add you to a meeting, regardless of whether you have the mobile app. **Call me** works over cellular connections instead of network connections, so you can attend a meeting even if you aren't connected to a network.
**Note**
You system administrator must enable **Call me**. If you can't complete the following steps, contact your adminstrator.
**To enable Call me**
1. Answer the call from a meeting, or select the link the link in the meeting invitation.
The **Device preview** dialog box appears.
1. Under **Audio settings**, choose the **Phone** tab.
1. Under **Call me**, choose a country from the **Call my phone number to dial in** list.
1. In the box below the list, enter the desired phone number.